Hot air furnace



y 3, 1934. F. B. FREELAND. 1,965,179

HOT AIR FURNACE Filed Nov. 14, 1931 INVENTOR Fred B. Freeland Patented July 3, 1934 uNrra H01 AIR FURNACE Fred B. Freeland, Dowagiac, Mich, assignor to Rudy Furnace Company, Dowagiac, Mich.

Application November 14,1931, Serial No. 574,964

3 Claims.

The main objects of this invention are:

First, to provide a hot air furnace which is provided with improved air circulating means, which add to the efiiciency of the furnace and 5 protect parts which have been subject to overheating.

Second, to provide improvements in furnaces producing this result which do not materially add to the cost of the furnace.

Third, to provide an improved hot air furnace having novel air circulating features which are automatically controlled.

Objects pertaining to details and economies of my invention will definitely appear from the description to follow. The invention is defined in the claims.

A structure which embodies the features of my invention is clearly illustrated in the accompanying drawing, in which:

Fig. 1 is a fragmentary vertical section of a hot air furnace embodying the features of my invention, with the parts in normal position, taken on a line corresponding to line 1-1 of Fig. 2.

Fig. 2 is a fragmentary front elevation.

Fig. 3 is an enlarged fragmentary section on line 33 of Fig. 2 showing the parts in the position occupied when the ash pit door is opened or partially opened in full lines, and in the position occupied when the ash pit door is closed in dotted lines.

Referring to the drawing, 1 represents the ashpit, 2 the firepot and 3 the radiator of a hot air furnace. These parts are disposed in super- 5 imposed relation and are provided with forwardly extending door extensions 4, 5 and 6, respec-- tively. The hot air casing '7 surrounds these several units, including their extensions. This casing includes a front plate 8 which is commonly a casting, and is provided with suitable openings registering with these extensions. The ashpit door 9 is hinged at 10 to swing in a horizontal plane. The hinges for the firepot door 11 and the clean-out door 12 are not illustrated.

It will be noted that there is a substantial space between the ashpit extension 4 and the firepot door extension 5. The front wall 8 is provided with an air inlet opening 13 to this space, this opening being provided with a door or closure 14 having hinges 15 at its upper edge so that the door closes by gravity. With this door open air enters into the space between the door extensions and flows upwardly around the firepot door extension and around the radiator and its clean-out extension 6. Air will also flow around the front side of the firepot and downwardly around the ashpit extensions, thus quite materially increasing the active radiating space of the furnace.

To automatically control the door 14 I provide an operating connection therefor to the ashpit door 9 which in the embodiment illustrated consists of a rocker arm 1'7 rockably arranged or seated in a hole 18 in the ledge 19 at the bottom of the inlet opening 13. This arm is provided with a downwardly projecting portion 20 positioned to be engaged by the tappet 21 on the ashpit door when the ashpit door is closed. The upper end of the rocker arm is then swung outwardly against the inner side of the closure 14, holding it in open position. However, when the ashpit door is open the air inlet door is closed by gravity so that dust from the ashpit or from taking up ashes cannot enter the hot air chamber through this air inlet opening 13. an important feature as it would be quite objectionable if the air inlet were left open during the taking up of ashes, for example.

This automatically acting connection prevents the air inlet door being inadvertently left open.

I have illustrated and described my improvements in a very practical and simple embodiment. I have not attempted to illustrate or describe other embodiments or adaptations which might be desirable for particular installations as it is believed that this disclosure will enable those skilled in the art to embody or adapt my improvements as may be most advantageous.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. The combination in a hot air furnace, of a firepot, ashpit and radiator with doc-r extensions disposed in vertically alined spaced relation, a hot air casing enclosing said door extensions and comprising a front plate having an air inlet opening between the firepot and ashpit extensions, a door for said air inlet opening hinged at its upper edge to close by gravity, an ashpit door hinged at one end to swing in a horizontal plane, and a rocker arm mounted on said front plate to engage the inner side of said air inlet door in close proximity to the pivotal mounting of the air inlet door, said rocker arm having an oppositely projecting portion of considerably less length than the rocker arm, and said ashpit door being provided with a tappet adapted to engage said portion of the rocker arm when in closed position for holding said air inlet door open.

This is 2. The combination in a hot air furnace including a firepot, ashpit and radiator provided with door extensions disposed in vertically alined spaced relation, of a hot air casing embracing said extensions and having an air inlet opening between the firepot and ashpit extensions, a door for said air inlet opening, an ashpit door, and a rocker arm mounted to engage said air inlet door in close proximity to the pivotal mounting of the air inlet door, said rocker arm having an oppositely projecting portion of considerably less length than the rocker arm, and said ashpit door being provided with a tappet adapted to engage portion of the said rocker arm when in closed position for holding said air inlet door open.

3. In a device of the class described, the combination of an air inlet door hinged to close by gravity and having an inclined seat, a ledge at the bottom of said seat and having a slot-like opening, an ashpit door hinged to swing horizontally and having an integral lug on its free edge, and a rocker arm disposed in said slotlike opening for bearing against the inner face of said air inlet door in close proximity to the pivotal mounting of the air inlet door and having shoulders resting on said ledge and a downwardly projecting portion positioned to be engaged by said lug said downwardly projecting portion being of considerably less length than the rocker arm, the rocker arm being free to tilt and open said air inlet door when said portion is engaged by said lug on the closing of said ashpit door and to release said air inlet door on the opening of said ashpit door, permitting the air inlet door to close by gravity.

FRED B. FREELAND. 

